I read the same arguments which I lump together in the category of "this time is different." To clear the baloney away one has to define what a stock or bond really is. Both are claims on a stream of cash flows paid to investors over time. If a company is buying back their stock that capital expenditure has done nothing to improve the earnings capacity of the company. In fact it is exactly the opposite, they have leveraged their future earnings capacity for a facade of growth. Bonds trading at historically low interest rates is a bet that central bank policies will continue to suppress price discovery. Who in their right mind would lend money for 50 years at a negative rate?
Of course one can continue to pick-up pennies in front of a steam roller. The facts are earnings are declining globally, their is broad weakness in certain sectors, regions and capitalization. The slightly positive year over year returns for the Dow and S&P 500 masks a most unstable and dangerous investment environment. And that goes for most asset classes.
The environment is most bizarre. Little of the conventional advice makes sense when measured against rational thinking or historical data. Investors are essentially making a bet that they can sell their stock or bond at the opportune time. It rarely is that easy and for every lucky investor there has to be an unlucky one. Someone has to own each stock or each bond until they are retired or mature.
In regards to governments spending, there are several examples of nations that can never repay their debt. At some point markets will reveal the "Come to Jesus" moment, and it won't be pretty.
Lastly, keep in mind how wrong people have been twice in the last 16 years. Use your brain, if the math doesn't add up, let it go. Patience is more than a virtue, in this environment for investors, it is required.